The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^...The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^(30)Si(^(3)He,d)^(31)P,^(13)B(d,^(3)He)^(12)Be,and^(34)S(^(3)He,d)^(35)Cl reactions at incident energies of 25,46,and 25 MeV,respectively,within the framework of the distorted wave Born approximation.The differential cross sections at the first peaks in the angular distributions of these reactions are found to have uncertainties of approximately 5%,owing to the uncertainties in the optical model potentials from 20,000 calculations of randomly sampled parameters.This amount of uncertainty is found to be nearly independent of the angular momentum transfer and the target masses within the studied range of incident energies.Uncertainties in the single proton spectroscopic factors obtained by matching the theoretical and experimental cross sections at different scattering angles are also discussed.展开更多
In the T-matrix form of the transfer reaction,the optical model potentials(OMPs)are used to compute the scattering wave function and transition operator.For most cases,the elastic scattering cross sections,normally us...In the T-matrix form of the transfer reaction,the optical model potentials(OMPs)are used to compute the scattering wave function and transition operator.For most cases,the elastic scattering cross sections,normally used to generate the OMPs,are not directly given in the same experiment.Then,the global OMPs,which fit the experimental data over a broad mass and energy range,are widely used in the theoretical calculations.Different sets of global OMPs with different parameter sets can reproduce the scattering cross section equally well within the uncertainty.Here,we apply different global OMPs to calculate the(differential)cross sections of(d,p)transfer reactions on the target nuclei^(12)C,^(48)Ca,^(124)Sn,and^(208)Pb at different energies.The results demonstrate that the effects of deuteron and nucleon global OMPs on transfer(differential)cross sections vary with energy and target mass.Furthermore,the influences of the spin-orbit coupling term of deuteron and nucleon global OMPs on the transfer cross sections are not negligible.展开更多
The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-b...The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.展开更多
This paper presents the results of a study that compares CTOM, a microscopic optical model potential(OMP), which is an optical model co-created by the China Nuclear Data Center & Tuebingen University, to CH89, whi...This paper presents the results of a study that compares CTOM, a microscopic optical model potential(OMP), which is an optical model co-created by the China Nuclear Data Center & Tuebingen University, to CH89, which is a typical phenomenological OMP.The respective OMPs were tested by applying them to the modelling of nucleon elastic scattering and(d,p) transfer reactions involving14C,36S, and58Ni targets at both low and relatively high energies. The results demonstrated that although both potentials successfully accounted for the angular distributions of both the elastic scattering and transfer cross sections, the absolute values of the transfer cross sections calculated using CTOM were approximately 25% larger than those calculated using CH89. This increased transfer cross sections allowed CTOM to produce single particle strength reduction factors for the three reactions that were consistent with those extracted from(e,e′p) reactions as well as with more recent(p,2p) and(p,pn) reactions. Notch tests suggested that nucleon elastic scattering and transfer reactions are sensitive to different regions of the OMP;accordingly,phenomenological OMPs, which are constrained only by elastic scattering cross sections, may not be sufficient for nucleon transfer reactions. Therefore, we suggest that microscopic OMPs, which reflect more theoretical considerations, should be preferred over phenomenological ones in calculations of direct nuclear reactions.展开更多
We construct a new global optical model potential to describe the elastic scattering of 12C.The experimental data of elastic-scattering angular distributions and total reaction cross sections for targets from 24Mg to ...We construct a new global optical model potential to describe the elastic scattering of 12C.The experimental data of elastic-scattering angular distributions and total reaction cross sections for targets from 24Mg to 209Bi are considered below 200 MeV within the framework of the optical model.The results calculated using the derived global optical potential are then compared with the existing experimental data.The reliability of the global optical potential is further tested by predicting the elastic scattering data out of the mass and energy ranges,within which the global potential parameters are determined,and reasonable results are also obtained.展开更多
We have compiled a sample of two subsets of AGN selected from their optical and X ray data. The first subset was selected for very broad and/or peculiar optical emission line profiles, the second for a high X ray flux...We have compiled a sample of two subsets of AGN selected from their optical and X ray data. The first subset was selected for very broad and/or peculiar optical emission line profiles, the second for a high X ray flux. Here we will discuss properties of these galaxies and show that both subsets are very similar in the multi wavelength view. Furthermore, we will discuss differences between the two subsets and their implications for a Unified Model of AGN.展开更多
Research on silicon-based tandem heterojunction solar cells (STHSC) incorporating metal oxides is one of the main directions for development of high-efficiency solar cells. In this work, the optical characteristics of...Research on silicon-based tandem heterojunction solar cells (STHSC) incorporating metal oxides is one of the main directions for development of high-efficiency solar cells. In this work, the optical characteristics of a STHSC consisting of a ZnO/Cu2O subcell on top of a silicon-based subcell were studied by optical modelling. Cu2O is a direct-gap p-type semiconductor which is attractive for application in solar cells due to its high absorptance of ultra-violet and visible light, nontoxicity, and low-cost producibility. Highly Al-doped ZnO and undoped Cu2O thin films were prepared on quartz substrates by magnetron sputter deposition. Thermal annealing of the Cu2O layer at 900°C enhances the electrical properties and reduces optical absorption, presumably as a result of increased grain size. Hall effect measurements show that the majority carrier (hole) mobility increases from 10 to 50 cm2/V×s and the resistivity decreases from 560 to 200 Ω×cm after annealing. A Cu2O absorber layer of 2 μm thickness will generate about 10 mA/cm2 of photocurrent under AM1.5G illumination. The optical analysis of the STHSC involved calculating the spectral curves for absorptance, transmittance, and reflectance for different thicknesses of the thin film layers constituting the ZnO/Cu2O subcell. The complex refractive indices of the thin films were derived from spectroscopic ellipsometry measurements and implemented in the simulation model. The lowest reflectance and highest transmittance for the ZnO/Cu2O subcell are obtained for a thickness of approximately 80 nm for both the top and bottom AZO layers. The SiNx anti-reflection coating for the c-Si bottom subcell must be optimized to accommodate the shift of the photon spectrum towards longer wavelengths. By increasing the thickness of the SiNx layer from 80 nm to 120 nm, the total reflectance for the STHSC device is reduced from 12.7% to 9.7%.展开更多
Wavelength-dependent mathematical modelling of the differential energy change of a photon has been performed inside a proposed hypothetical optical medium.The existence of this medium demands certain mathematical cons...Wavelength-dependent mathematical modelling of the differential energy change of a photon has been performed inside a proposed hypothetical optical medium.The existence of this medium demands certain mathematical constraints,which have been derived in detail.Using reverse modelling,a medium satisfying the derived conditions is proven to store energy as the photon propagates from the entry to exit point.A single photon with a given intensity is considered in the analysis and hypothesized to possess a definite non-zero probability of maintaining its energy and velocity functions analytic inside the proposed optical medium,despite scattering,absorption,fluorescence,heat generation,and other nonlinear mechanisms.The energy and velocity functions are thus singly and doubly differentiable with respect to wavelength.The solution of the resulting second-order differential equation in two variables proves that energy storage or energy flotation occurs inside a medium with a refractive index satisfying the described mathematical constraints.The minimum-value-normalized refractive index profiles of the modelled optical medium for transformed wavelengths both inside the medium and for vacuum have been derived.Mathematical proofs,design equations,and detailed numerical analyses are presented in the paper.展开更多
BACKGROUND: Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models a...BACKGROUND: Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models are greatly different from anterior ischemia optic neuropathy. Therefore, a more ideal method is needed to establish animal model of anterior ischemic optic neuropathy (AION).OBJECTIVE: To establish AION models in rats, observe the functional changes of fundus, fundus fluorescein angiography (FFA), optical coherence tomography (OCT), flash visual evoked potential (F-VEP), and histopathologically confirm its reliability.DESIGN: A randomized control trial.SETTINGS: Department of Ophthalmology, Xi’an Fourth Hospital; Xi’an Institute of Ocular Fundus Diseases.MATERIALS: The experiments were carried out in the research room of Xi’an Institute of Ocular Fundus Diseases from February 2005 to May 2006. Thirty healthy male SD rats of 4-5 weeks old, weighing 140-160 g, were provided by the animal experimental center of the Fourth Military Medical University of Chinese PLA [SCXK(Military)2002-005], and those without eye disease examined by slit lamp and direct ophthalmoscope after mydriasis were enrolled. The conditions for feeding mice without special pathogen were strictly followed. The rats were randomly divided into blank control group (n =5), laser group (n =5), hematoporphyrin derivative (HPD) group and AION group (n =15), each group was numbered randomly. For each rat, the right eye was taken as the experimental eye, and the left one as the control one.METHODS: In the AION group, the rats were injected with HPD (10 mg/kg) via caudal vein, and then the optic discs were exposed to krypton red (647 nm, 80 mV) for 120 s, and the rats were in avoidance of light for 2 weeks postoperatively. Rats in the laser group were only exposed to krypton red (647 nm, 80 mV) for 120 s, and in avoidance of light for 2 weeks postoperatively; Those in the HPD group were only injected with HPD (10 mg/kg) via caudal vein; Those in the blank control group were untouched. ① Visual electrophysiological test: The F-VEP was used to evaluate the function of visual nerve. ② FFA: After mydriasis and anesthesia as describe above, the fluorescein sodium parenteral solution (1 mL/kg) was injected via caudal vein and finished within about 3 s, the time of FFA was recorded from the beginning of injection, the video sight aimed at the optic disc and the surrounding area. ③ After mydriasis and anesthesia as describe above, the rats were examined with OCT. ④ Histological observation: After hematoxylin and eosin (HE) staining, the optic disc and surrounding blood vessels of retina were observed under light microscope at high power field. MAIN OUTCOME MEASURES: The results of fundus, FFA, visual electrophysiological test and OCT detection within 90 days after model establishment were observed. RESULTS: Of the 30 rats, 1 died after anesthesia in the laser group and 2 died in the AION group respectively, and finally 27 rats were involved in the analysis of results. ① Changes in fundus: In the AION group, there was edema in upper optic disc and unclear boundary at 1 day after establishment, edema still could be observed at 6 days, and upper optic disc atrophied and appeared as pale at 90 days. ② FFA results: In the AION group, early "low fluorescence", middle and late "high fluorescence" were observed in upper optic disc 1 day after model establishment, and there was "low fluorescence" at 6 days, and the low fluorescence could be observed all the time at 23 days. ③ Visual electrophysiological changes: In the AION group as compared with the control eyes, the experimental ones had prolonged F-VEP P100 latency [(71.65±8.81), (57.58±8.38) ms, t =3.148, P =0.012], and decreased wave amplitude [(4.77±1.90), (10.06±3.66) μV, t =4.082, P =0.003], and these changes lasted to 35 days after model establishment. ④ OCT results: In the AION group, the reflection surface of part nerve fiber layer was higher than the retina plane, the surface was rough and the thickness was increased at 6 days after model establishment. ⑤ Histopathological results: At 1 day after model establishment, part optic discs had highly edema, edema of nerve fibers, and loose tissue, also accompanied by the displacement of surrounding retina; At 23 days, the optic disc and surrounding nerve fiber layers became thinner, and the numbers of ganglion nuclei in the retina tissue sections were obviously decreased. These changes were not observed in the laser group, HPD group and blank control group. CONCLUSION: The changes of fundus, FFA, OCT, visual electrophysiology and histopathology confirmed that the krypton red laser irradiation (647 nm) at 2 hours after HPD was injected via caudal vein can establish more ideal animal models of AION.展开更多
As one type of spatially offset Raman spectroscopy(SORS), inverse SORS is particularly suited to in vivo biomedical measurements due to its ring-shaped illumination scheme. To explain inhomogeneous Raman scattering du...As one type of spatially offset Raman spectroscopy(SORS), inverse SORS is particularly suited to in vivo biomedical measurements due to its ring-shaped illumination scheme. To explain inhomogeneous Raman scattering during in vivo inverse SORS measurements, the light–tissue interactions when excitation and regenerated Raman photons propagate in skin tissue were studied using Monte Carlo simulation. An eight-layered skin model was first built based on the latest transmission parameters. Then, an open-source platform, Monte Carlo e Xtreme(MCX), was adapted to study the distribution of 785 nm excitation photons inside the model with an inverse spatially shifted annular beam. The excitation photons were converted to emission photons by an inverse distribution method based on excitation flux with spatial offsets Δs of 1 mm, 2 mm, 3 mm and 5 mm. The intrinsic Raman spectra from separated skin layers were measured by continuous linear scanning to improve the simulation accuracy. The obtained results explain why the spectral detection depth gradually increases with increasing spatial offset, and address how the intrinsic Raman spectrum from deep skin layers is distorted by the reabsorption and scattering of the superficial tissue constituents. Meanwhile, it is demonstrated that the spectral contribution from subcutaneous fat will be improved when the offset increases to 5 mm, and the highest detection efficiency for dermal layer spectral detection could be achieved when Δs = 2 mm. Reasonably good matching between the calculated spectrum and the measured in vivo inverse SORS was achieved, thus demonstrating great utility of our modeling method and an approach to help understand the clinical measurements.展开更多
In this paper, we give a definition of the Fermi function, or the so-called Woods-Saxon potential, a well-known potential in nuclear physics;then, we give a few of its applications as examples. Some important integral...In this paper, we give a definition of the Fermi function, or the so-called Woods-Saxon potential, a well-known potential in nuclear physics;then, we give a few of its applications as examples. Some important integrals, which involve this function, are computed discussing the integrability and convergence of these integrals. Following, we derive formulae that encounter the above-mentioned function to get nuclear and generalized moments;the radial Fourier transformation is also exposed. Some related applications are then given that use such important integrals;in particular, we give the computation in conjunction with the problem of getting the optical-model potential for heavy-ion interactions at intermediate energies. Finally, we conclude with important remarks to do with the evolution of the subject.展开更多
In this paper,a new M3Y-type effective nucleon–nucleon interaction,derived based on the lowest order constrained variational approach(LOCV)and termed B3Y-Fetal,has been used in DDM3Y1,BDM3Y1,BDM3Y2,and BDM3Y3 density...In this paper,a new M3Y-type effective nucleon–nucleon interaction,derived based on the lowest order constrained variational approach(LOCV)and termed B3Y-Fetal,has been used in DDM3Y1,BDM3Y1,BDM3Y2,and BDM3Y3 density-dependent versions in a heavy ion(HI)optical potential based on four types of a real folded potential and a phenomenological Woods–Saxon imaginary potential to study the elastic scattering of the^(16)O+^(16)O nuclear system within the framework of the optical model(OM)by computing the associated differential cross sections at various incident energies.The results of the folding analyses have shown the DDB3Y1-Fetal and BDB3Y1-Fetal,out of the four folded potentials,give a reasonably better description of the elastic data of the nuclear system.These best-fit folded potentials are followed,in performance,by the BDB3Y2-Fetal,with the BDB3Y3-Fetal potential coming last.This performance trend was also demonstrated by the optical potentials based on the M3Y-Reid interaction.Furthermore,the best-fit folded potentials,renormalized by a factor NRof approximately 0.9,have been shown to reproduce the energy dependence of the real optical potential for^(16)O scattering found in previous optical model analyses creditably well.In excellent agreement with previous works,they have also been identified in this work to belong to the family of deep refractive potentials because they have been able to reproduce and consistently describe the evolution of Airylike structures,at large scattering angles,observed in the^(16)O scattering data at different energies.Finally,a comparison of the performances of B3Y-Fetal and M3Y-Reid effective interactions undertaken in this work has shown impressive agreement between them.展开更多
In this paper, we develop a theoretical method based on ray optics to calculate the optical force and torque on a metallo-dielectric Janus particle in an optical trap made from a tightly focused Gaussian beam. The Jan...In this paper, we develop a theoretical method based on ray optics to calculate the optical force and torque on a metallo-dielectric Janus particle in an optical trap made from a tightly focused Gaussian beam. The Janus particle is a 2.8 μm diameter polystyrene sphere half-coated with gold thin film several nanometers in thickness. The calculation result shows that the focused beam will push the Janus particle away from the center of the trap,and the equilibrium position of the Janus particle, where the optical force and torque are both zero, is located in a circular orbit surrounding the laser beam axis. The theoretical results are in good agreement qualitatively and quantitatively with our experimental observation. As the ray-optics model is simple in principle, user friendly in formalism, and cost effective in terms of computation resources and time compared with other usual rigorous electromagnetics approaches, the developed theoretical method can become an invaluable tool for understanding and designing ways to control the mechanical motion of complicated microscopic particles in various optical tweezers.展开更多
Aiming at the problem of scanning distortion in X-Y galvanometer light detecting and ranging(Lidar) scanning system,we propose a method of image scanning distortion correction with controllable driving voltage compens...Aiming at the problem of scanning distortion in X-Y galvanometer light detecting and ranging(Lidar) scanning system,we propose a method of image scanning distortion correction with controllable driving voltage compensation.Firstly,the geometrical optics vectors model is established to explain the principle of pincushion distortion in the galvanometer scanning system,and the simulation result of scanning trajectory is consistent with experiments.The linear relationship between the driving voltage and the scanning angle of the galvanometer is verified.Secondly,the relationship between the deflection angle of the galvanometer and the scanning trajectory and the driving voltage is deduced respectively,and an image scanning correction algorithm with controllable driving voltage compensation is obtained.The simulation experiment results of the proposed method show that the root-mean-square error(RMSE) and the corresponding curve between the scan value and the actual value at different distances,have a good correction effect for the pincushion distortion.Finally,the X-Y galvanometer scanning Lidar system is established to obtain undistorted two-dimensional scanned image and it can be applied to the three-dimensional Lidar scanning system in the actual experiments,which further demonstrates the feasibility and practicability of our method.展开更多
Pricing of the optical networks will play a key role from network operator's point of view to achieve the maximum profit. This paper introduces pricing models for optical networks.
1 IntroductionLiNbO3 optical modulators have become essential transmission devices for current and future wideband fibre-optic communications for both military and telecommunications applications. For many telecommuni...1 IntroductionLiNbO3 optical modulators have become essential transmission devices for current and future wideband fibre-optic communications for both military and telecommunications applications. For many telecommunications applications, only a narrow bandwidth is required and thus resonantly enhancedMach-Zehndermodulators(RE-MZMs)have been developed to improve modulation efficiency at the expense of bandwidth.展开更多
The elastic scattering angular distributions of ^(13)C at 340 MeV and ^(14)C at 294 MeV and 342 MeV on a ^(208)Pb target,which correspond to approximately five times the Coulomb barriers,were measured at the Radioacti...The elastic scattering angular distributions of ^(13)C at 340 MeV and ^(14)C at 294 MeV and 342 MeV on a ^(208)Pb target,which correspond to approximately five times the Coulomb barriers,were measured at the Radioactive Ion Beam Line in Lanzhou.The data were analyzed within the optical model and continuum-discretized coupled-channels(CDCC)framework,and the results of both calculations could effectively account for the experimental data.The differential cross sections of elastic scattering revealed no particular suppression at the Coulomb nuclear interference peak angles,suggesting that the breakup coupling effects on the elastic scattering angular distributions were negligibly small in this incident energy region.The contributions from the couplings with inelastic states to the elastic cross sections were of minor importance within the angular range covered by these experiments.展开更多
We achieved a set of 9Be global phenomenological optical model potentials by fitting a large experimental dataset of the elastic scattering observable for target mass numbers from 24 to 209.The obtained 9Be global opt...We achieved a set of 9Be global phenomenological optical model potentials by fitting a large experimental dataset of the elastic scattering observable for target mass numbers from 24 to 209.The obtained 9Be global optical model potential was applied to predict elastic-scattering angular distributions and total reaction cross-sections of 8,10,11B projectiles.The predictions are made by performing a detailed analysis comparing with the available experimental data.Furthermore,these elastic scattering observables are also predicted for some lighter targets outside of the given mass number range,and reasonable results are obtained.Possible physical explanations for the observed differences are also discussed.展开更多
基金supported by the National Natural Science Foundation of China(No.U2067205).
文摘The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^(30)Si(^(3)He,d)^(31)P,^(13)B(d,^(3)He)^(12)Be,and^(34)S(^(3)He,d)^(35)Cl reactions at incident energies of 25,46,and 25 MeV,respectively,within the framework of the distorted wave Born approximation.The differential cross sections at the first peaks in the angular distributions of these reactions are found to have uncertainties of approximately 5%,owing to the uncertainties in the optical model potentials from 20,000 calculations of randomly sampled parameters.This amount of uncertainty is found to be nearly independent of the angular momentum transfer and the target masses within the studied range of incident energies.Uncertainties in the single proton spectroscopic factors obtained by matching the theoretical and experimental cross sections at different scattering angles are also discussed.
基金Supported by the National Natural Science Foundation of China(12035011,11975167,11535004,11947211,11905103,11761161001,11375086,11565010,11881240623,11961141003)the National Key R&D Program of China(2018YFA0404403,2016YFE0129300)+1 种基金the Science and Technology Development Fund of Macao(008/2017/AFJ)the Fundamental Research Funds for the Central Universities(22120200101)。
文摘In the T-matrix form of the transfer reaction,the optical model potentials(OMPs)are used to compute the scattering wave function and transition operator.For most cases,the elastic scattering cross sections,normally used to generate the OMPs,are not directly given in the same experiment.Then,the global OMPs,which fit the experimental data over a broad mass and energy range,are widely used in the theoretical calculations.Different sets of global OMPs with different parameter sets can reproduce the scattering cross section equally well within the uncertainty.Here,we apply different global OMPs to calculate the(differential)cross sections of(d,p)transfer reactions on the target nuclei^(12)C,^(48)Ca,^(124)Sn,and^(208)Pb at different energies.The results demonstrate that the effects of deuteron and nucleon global OMPs on transfer(differential)cross sections vary with energy and target mass.Furthermore,the influences of the spin-orbit coupling term of deuteron and nucleon global OMPs on the transfer cross sections are not negligible.
基金Supported by National Natural Science Foundation of China(Nos.U2067205 and 12205098)National Key Laboratory of Computational Physics(HX02021-35).
文摘The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.
基金supported by the National Natural Science Foundation of China(Grant Nos.11775013,U1432247,11775316,U1630143,and 11465005)the National Key Research and Development Program(Grant No.2016YFA0400502)Science Challenge Project(Grant No.TZ2018001)
文摘This paper presents the results of a study that compares CTOM, a microscopic optical model potential(OMP), which is an optical model co-created by the China Nuclear Data Center & Tuebingen University, to CH89, which is a typical phenomenological OMP.The respective OMPs were tested by applying them to the modelling of nucleon elastic scattering and(d,p) transfer reactions involving14C,36S, and58Ni targets at both low and relatively high energies. The results demonstrated that although both potentials successfully accounted for the angular distributions of both the elastic scattering and transfer cross sections, the absolute values of the transfer cross sections calculated using CTOM were approximately 25% larger than those calculated using CH89. This increased transfer cross sections allowed CTOM to produce single particle strength reduction factors for the three reactions that were consistent with those extracted from(e,e′p) reactions as well as with more recent(p,2p) and(p,pn) reactions. Notch tests suggested that nucleon elastic scattering and transfer reactions are sensitive to different regions of the OMP;accordingly,phenomenological OMPs, which are constrained only by elastic scattering cross sections, may not be sufficient for nucleon transfer reactions. Therefore, we suggest that microscopic OMPs, which reflect more theoretical considerations, should be preferred over phenomenological ones in calculations of direct nuclear reactions.
基金Supported by China National Natural Science Foundation(11405099,11575291,12065003)by Scientific and Technological Innovation Programs of Higher Education Institutions(STIP)in Shanxi of China(2019L0743)+1 种基金by Science Foundation for General in Shanxi of China(201901D111317)This work is also a part of IAEA Coordinated Research Projects(CRPs)on Recommended Input Parameter Library(RIPL)for Fission Cross Section Calculations(20464)。
文摘We construct a new global optical model potential to describe the elastic scattering of 12C.The experimental data of elastic-scattering angular distributions and total reaction cross sections for targets from 24Mg to 209Bi are considered below 200 MeV within the framework of the optical model.The results calculated using the derived global optical potential are then compared with the existing experimental data.The reliability of the global optical potential is further tested by predicting the elastic scattering data out of the mass and energy ranges,within which the global potential parameters are determined,and reasonable results are also obtained.
文摘We have compiled a sample of two subsets of AGN selected from their optical and X ray data. The first subset was selected for very broad and/or peculiar optical emission line profiles, the second for a high X ray flux. Here we will discuss properties of these galaxies and show that both subsets are very similar in the multi wavelength view. Furthermore, we will discuss differences between the two subsets and their implications for a Unified Model of AGN.
基金conducted under the research project“High-performance tandem heterojunction solar cells for specific applications(SOLHET)”,financially supported by the Research Council of Norway(RCN)and the Romanian Executive Agency for Higher Education,Research,Development and Innovation Funding(UEFISCDI)through the M-Era.net program.
文摘Research on silicon-based tandem heterojunction solar cells (STHSC) incorporating metal oxides is one of the main directions for development of high-efficiency solar cells. In this work, the optical characteristics of a STHSC consisting of a ZnO/Cu2O subcell on top of a silicon-based subcell were studied by optical modelling. Cu2O is a direct-gap p-type semiconductor which is attractive for application in solar cells due to its high absorptance of ultra-violet and visible light, nontoxicity, and low-cost producibility. Highly Al-doped ZnO and undoped Cu2O thin films were prepared on quartz substrates by magnetron sputter deposition. Thermal annealing of the Cu2O layer at 900°C enhances the electrical properties and reduces optical absorption, presumably as a result of increased grain size. Hall effect measurements show that the majority carrier (hole) mobility increases from 10 to 50 cm2/V×s and the resistivity decreases from 560 to 200 Ω×cm after annealing. A Cu2O absorber layer of 2 μm thickness will generate about 10 mA/cm2 of photocurrent under AM1.5G illumination. The optical analysis of the STHSC involved calculating the spectral curves for absorptance, transmittance, and reflectance for different thicknesses of the thin film layers constituting the ZnO/Cu2O subcell. The complex refractive indices of the thin films were derived from spectroscopic ellipsometry measurements and implemented in the simulation model. The lowest reflectance and highest transmittance for the ZnO/Cu2O subcell are obtained for a thickness of approximately 80 nm for both the top and bottom AZO layers. The SiNx anti-reflection coating for the c-Si bottom subcell must be optimized to accommodate the shift of the photon spectrum towards longer wavelengths. By increasing the thickness of the SiNx layer from 80 nm to 120 nm, the total reflectance for the STHSC device is reduced from 12.7% to 9.7%.
文摘Wavelength-dependent mathematical modelling of the differential energy change of a photon has been performed inside a proposed hypothetical optical medium.The existence of this medium demands certain mathematical constraints,which have been derived in detail.Using reverse modelling,a medium satisfying the derived conditions is proven to store energy as the photon propagates from the entry to exit point.A single photon with a given intensity is considered in the analysis and hypothesized to possess a definite non-zero probability of maintaining its energy and velocity functions analytic inside the proposed optical medium,despite scattering,absorption,fluorescence,heat generation,and other nonlinear mechanisms.The energy and velocity functions are thus singly and doubly differentiable with respect to wavelength.The solution of the resulting second-order differential equation in two variables proves that energy storage or energy flotation occurs inside a medium with a refractive index satisfying the described mathematical constraints.The minimum-value-normalized refractive index profiles of the modelled optical medium for transformed wavelengths both inside the medium and for vacuum have been derived.Mathematical proofs,design equations,and detailed numerical analyses are presented in the paper.
基金a grant from Scientific Research Fund of Shaanxi Department of Hygiene, No. 04AC1
文摘BACKGROUND: Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models are greatly different from anterior ischemia optic neuropathy. Therefore, a more ideal method is needed to establish animal model of anterior ischemic optic neuropathy (AION).OBJECTIVE: To establish AION models in rats, observe the functional changes of fundus, fundus fluorescein angiography (FFA), optical coherence tomography (OCT), flash visual evoked potential (F-VEP), and histopathologically confirm its reliability.DESIGN: A randomized control trial.SETTINGS: Department of Ophthalmology, Xi’an Fourth Hospital; Xi’an Institute of Ocular Fundus Diseases.MATERIALS: The experiments were carried out in the research room of Xi’an Institute of Ocular Fundus Diseases from February 2005 to May 2006. Thirty healthy male SD rats of 4-5 weeks old, weighing 140-160 g, were provided by the animal experimental center of the Fourth Military Medical University of Chinese PLA [SCXK(Military)2002-005], and those without eye disease examined by slit lamp and direct ophthalmoscope after mydriasis were enrolled. The conditions for feeding mice without special pathogen were strictly followed. The rats were randomly divided into blank control group (n =5), laser group (n =5), hematoporphyrin derivative (HPD) group and AION group (n =15), each group was numbered randomly. For each rat, the right eye was taken as the experimental eye, and the left one as the control one.METHODS: In the AION group, the rats were injected with HPD (10 mg/kg) via caudal vein, and then the optic discs were exposed to krypton red (647 nm, 80 mV) for 120 s, and the rats were in avoidance of light for 2 weeks postoperatively. Rats in the laser group were only exposed to krypton red (647 nm, 80 mV) for 120 s, and in avoidance of light for 2 weeks postoperatively; Those in the HPD group were only injected with HPD (10 mg/kg) via caudal vein; Those in the blank control group were untouched. ① Visual electrophysiological test: The F-VEP was used to evaluate the function of visual nerve. ② FFA: After mydriasis and anesthesia as describe above, the fluorescein sodium parenteral solution (1 mL/kg) was injected via caudal vein and finished within about 3 s, the time of FFA was recorded from the beginning of injection, the video sight aimed at the optic disc and the surrounding area. ③ After mydriasis and anesthesia as describe above, the rats were examined with OCT. ④ Histological observation: After hematoxylin and eosin (HE) staining, the optic disc and surrounding blood vessels of retina were observed under light microscope at high power field. MAIN OUTCOME MEASURES: The results of fundus, FFA, visual electrophysiological test and OCT detection within 90 days after model establishment were observed. RESULTS: Of the 30 rats, 1 died after anesthesia in the laser group and 2 died in the AION group respectively, and finally 27 rats were involved in the analysis of results. ① Changes in fundus: In the AION group, there was edema in upper optic disc and unclear boundary at 1 day after establishment, edema still could be observed at 6 days, and upper optic disc atrophied and appeared as pale at 90 days. ② FFA results: In the AION group, early "low fluorescence", middle and late "high fluorescence" were observed in upper optic disc 1 day after model establishment, and there was "low fluorescence" at 6 days, and the low fluorescence could be observed all the time at 23 days. ③ Visual electrophysiological changes: In the AION group as compared with the control eyes, the experimental ones had prolonged F-VEP P100 latency [(71.65±8.81), (57.58±8.38) ms, t =3.148, P =0.012], and decreased wave amplitude [(4.77±1.90), (10.06±3.66) μV, t =4.082, P =0.003], and these changes lasted to 35 days after model establishment. ④ OCT results: In the AION group, the reflection surface of part nerve fiber layer was higher than the retina plane, the surface was rough and the thickness was increased at 6 days after model establishment. ⑤ Histopathological results: At 1 day after model establishment, part optic discs had highly edema, edema of nerve fibers, and loose tissue, also accompanied by the displacement of surrounding retina; At 23 days, the optic disc and surrounding nerve fiber layers became thinner, and the numbers of ganglion nuclei in the retina tissue sections were obviously decreased. These changes were not observed in the laser group, HPD group and blank control group. CONCLUSION: The changes of fundus, FFA, OCT, visual electrophysiology and histopathology confirmed that the krypton red laser irradiation (647 nm) at 2 hours after HPD was injected via caudal vein can establish more ideal animal models of AION.
基金Project supported by the National Natural Science Foundation of China (Grant No. 61911530695)the Key Research and Development Project of Shaanxi Province, China (Grant No. 2023-YBSF-671)。
文摘As one type of spatially offset Raman spectroscopy(SORS), inverse SORS is particularly suited to in vivo biomedical measurements due to its ring-shaped illumination scheme. To explain inhomogeneous Raman scattering during in vivo inverse SORS measurements, the light–tissue interactions when excitation and regenerated Raman photons propagate in skin tissue were studied using Monte Carlo simulation. An eight-layered skin model was first built based on the latest transmission parameters. Then, an open-source platform, Monte Carlo e Xtreme(MCX), was adapted to study the distribution of 785 nm excitation photons inside the model with an inverse spatially shifted annular beam. The excitation photons were converted to emission photons by an inverse distribution method based on excitation flux with spatial offsets Δs of 1 mm, 2 mm, 3 mm and 5 mm. The intrinsic Raman spectra from separated skin layers were measured by continuous linear scanning to improve the simulation accuracy. The obtained results explain why the spectral detection depth gradually increases with increasing spatial offset, and address how the intrinsic Raman spectrum from deep skin layers is distorted by the reabsorption and scattering of the superficial tissue constituents. Meanwhile, it is demonstrated that the spectral contribution from subcutaneous fat will be improved when the offset increases to 5 mm, and the highest detection efficiency for dermal layer spectral detection could be achieved when Δs = 2 mm. Reasonably good matching between the calculated spectrum and the measured in vivo inverse SORS was achieved, thus demonstrating great utility of our modeling method and an approach to help understand the clinical measurements.
文摘In this paper, we give a definition of the Fermi function, or the so-called Woods-Saxon potential, a well-known potential in nuclear physics;then, we give a few of its applications as examples. Some important integrals, which involve this function, are computed discussing the integrability and convergence of these integrals. Following, we derive formulae that encounter the above-mentioned function to get nuclear and generalized moments;the radial Fourier transformation is also exposed. Some related applications are then given that use such important integrals;in particular, we give the computation in conjunction with the problem of getting the optical-model potential for heavy-ion interactions at intermediate energies. Finally, we conclude with important remarks to do with the evolution of the subject.
基金Prof.Dao T.Khoa of the Institute for Nuclear Science and Technology(INST),Vietnam,is specially and gratefully acknowledged for providing helpful academic materials and excellent guidance in this work.
文摘In this paper,a new M3Y-type effective nucleon–nucleon interaction,derived based on the lowest order constrained variational approach(LOCV)and termed B3Y-Fetal,has been used in DDM3Y1,BDM3Y1,BDM3Y2,and BDM3Y3 density-dependent versions in a heavy ion(HI)optical potential based on four types of a real folded potential and a phenomenological Woods–Saxon imaginary potential to study the elastic scattering of the^(16)O+^(16)O nuclear system within the framework of the optical model(OM)by computing the associated differential cross sections at various incident energies.The results of the folding analyses have shown the DDB3Y1-Fetal and BDB3Y1-Fetal,out of the four folded potentials,give a reasonably better description of the elastic data of the nuclear system.These best-fit folded potentials are followed,in performance,by the BDB3Y2-Fetal,with the BDB3Y3-Fetal potential coming last.This performance trend was also demonstrated by the optical potentials based on the M3Y-Reid interaction.Furthermore,the best-fit folded potentials,renormalized by a factor NRof approximately 0.9,have been shown to reproduce the energy dependence of the real optical potential for^(16)O scattering found in previous optical model analyses creditably well.In excellent agreement with previous works,they have also been identified in this work to belong to the family of deep refractive potentials because they have been able to reproduce and consistently describe the evolution of Airylike structures,at large scattering angles,observed in the^(16)O scattering data at different energies.Finally,a comparison of the performances of B3Y-Fetal and M3Y-Reid effective interactions undertaken in this work has shown impressive agreement between them.
基金supported by the 973 Program of China (no. 2013CB632704)the National Natural Science Foundation of China (no. 11434017)
文摘In this paper, we develop a theoretical method based on ray optics to calculate the optical force and torque on a metallo-dielectric Janus particle in an optical trap made from a tightly focused Gaussian beam. The Janus particle is a 2.8 μm diameter polystyrene sphere half-coated with gold thin film several nanometers in thickness. The calculation result shows that the focused beam will push the Janus particle away from the center of the trap,and the equilibrium position of the Janus particle, where the optical force and torque are both zero, is located in a circular orbit surrounding the laser beam axis. The theoretical results are in good agreement qualitatively and quantitatively with our experimental observation. As the ray-optics model is simple in principle, user friendly in formalism, and cost effective in terms of computation resources and time compared with other usual rigorous electromagnetics approaches, the developed theoretical method can become an invaluable tool for understanding and designing ways to control the mechanical motion of complicated microscopic particles in various optical tweezers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61775048 and 62027823)the Natural Science Foundation of Shenzhen(Grant No.JCYJ2020109150808037)。
文摘Aiming at the problem of scanning distortion in X-Y galvanometer light detecting and ranging(Lidar) scanning system,we propose a method of image scanning distortion correction with controllable driving voltage compensation.Firstly,the geometrical optics vectors model is established to explain the principle of pincushion distortion in the galvanometer scanning system,and the simulation result of scanning trajectory is consistent with experiments.The linear relationship between the driving voltage and the scanning angle of the galvanometer is verified.Secondly,the relationship between the deflection angle of the galvanometer and the scanning trajectory and the driving voltage is deduced respectively,and an image scanning correction algorithm with controllable driving voltage compensation is obtained.The simulation experiment results of the proposed method show that the root-mean-square error(RMSE) and the corresponding curve between the scan value and the actual value at different distances,have a good correction effect for the pincushion distortion.Finally,the X-Y galvanometer scanning Lidar system is established to obtain undistorted two-dimensional scanned image and it can be applied to the three-dimensional Lidar scanning system in the actual experiments,which further demonstrates the feasibility and practicability of our method.
文摘Pricing of the optical networks will play a key role from network operator's point of view to achieve the maximum profit. This paper introduces pricing models for optical networks.
文摘1 IntroductionLiNbO3 optical modulators have become essential transmission devices for current and future wideband fibre-optic communications for both military and telecommunications applications. For many telecommunications applications, only a narrow bandwidth is required and thus resonantly enhancedMach-Zehndermodulators(RE-MZMs)have been developed to improve modulation efficiency at the expense of bandwidth.
基金Supported by the National Natural Science Foundation of China (12122511,12105330)the Youth Innovation Promotion Association CAS (2020411)+1 种基金funding from the State Key Laboratory of Nuclear Physics and Technology,Peking University (NPT2023KFY04)V.G.would like to thank CNPq (303769/2021-1).
文摘The elastic scattering angular distributions of ^(13)C at 340 MeV and ^(14)C at 294 MeV and 342 MeV on a ^(208)Pb target,which correspond to approximately five times the Coulomb barriers,were measured at the Radioactive Ion Beam Line in Lanzhou.The data were analyzed within the optical model and continuum-discretized coupled-channels(CDCC)framework,and the results of both calculations could effectively account for the experimental data.The differential cross sections of elastic scattering revealed no particular suppression at the Coulomb nuclear interference peak angles,suggesting that the breakup coupling effects on the elastic scattering angular distributions were negligibly small in this incident energy region.The contributions from the couplings with inelastic states to the elastic cross sections were of minor importance within the angular range covered by these experiments.
基金Supported by the National Natural Science Foundation of China(11405099 and 11575291)a part of IAEA Coordinated Research Projects(CRPs)on Recommended Input Parameter Library(RIPL)for Fission Cross Section Calculations(20464)
文摘We achieved a set of 9Be global phenomenological optical model potentials by fitting a large experimental dataset of the elastic scattering observable for target mass numbers from 24 to 209.The obtained 9Be global optical model potential was applied to predict elastic-scattering angular distributions and total reaction cross-sections of 8,10,11B projectiles.The predictions are made by performing a detailed analysis comparing with the available experimental data.Furthermore,these elastic scattering observables are also predicted for some lighter targets outside of the given mass number range,and reasonable results are obtained.Possible physical explanations for the observed differences are also discussed.
